With cats now becoming the most popular type of domestic pet, the use of kitty litter boxes continues to increase proportionally. Kitty litter boxes are normally made of plastic or similar material so that the cat's urine will not leak through the box. The box has placed in it one of any number of particulate kitty litter material meant to absorb moisture and odor from the cat's waste, as well as provide clumping agents so that the cat's liquid waste may solidify. These particulate materials are generally referred to as kitty litter. Cats also tend to bury their solid waste in the kitty litter.
General practice for most cat owners is to discard the kitty litter after an extended period of time. However, before the kitty litter has reached a state where it needs to be totally dumped, it is often necessary to periodically remove the cat's solid waste in order to prevent it from being kicked out of the litter box by the cat upon subsequent visits to the litter box, so that the cat or other animals do not step on the solid waste, thereby transferring it to other areas and causing a potential mess.
Many cat owners find the task of manually searching the kitty litter for solid waste to be obnoxious and burdensome. Thus, inventors have sought to devise ways of cleaning the solid waste automatically from kitty litter boxes. Patents showing devices for cleaning litter boxes include U.S. Pat. Nos. 4,096,827; 4,180,804; 4,190,525; 4,325,325; and 4,325,822. More recently, the inventor's licensee has commercialized a self-cleaning litter box, covered by U.S. Pat. No. 5,048,465 and issued to the inventor of the present invention, and U.S. Pat. No. 5,477,812, which discloses a self-cleaning litter box. While such litter box is self-cleaning, the solid waste holder, when full, must be slid out of the housing so that the solid waste may be dumped.
When a cat owner is away for a significant period of time or is otherwise unable to dump the tray, the cat's solid waste may collect and overflow the tray, which is unsightly and potentially messy due to the cats kicking it from box, etc. In other embodiments of the self-cleaning cat tray, a sensor provided in cooperation with the lid may cause the unit to cease operating when the tray becomes filled to a pre-determined limit, such as when the lid is oriented away from its rest position.
Accordingly, there is a need for a device which is capable of accommodating a cat owner's absence or inability to dump solid waste from kitty litter boxes at intervals required by typical litter boxes. Such device should also be compatible with current self-cleaning kitty litter box designs, should be easy to operate, easy to clean, easy to assemble, and easy and inexpensive to manufacture.